The African American race continues to be an important surrogate for an excess prevalence of chronic disease and adverse sequela in the United States. One important example is that African Americans in their third and fourth decades of life harbor a striking 18-fold increase in the incidence of hypertensive End-Stage Renal Disease (ESRD) when compared to their white counterparts. Racial diversity in biochemical parameters associated with hypertension taken with the excess prevalence of hypertensive ESRD has led to the proposal that hypertension and its consequences have a unique etiology in African Americans. Large hypertension trials have focused on cardiac and stroke complications with less attention paid to renal disease. It is not known whether the presumed lack of effectiveness of antihypertensive therapy, and the postulated racial differences in renal outcomes are due to inadequate control of blood pressure or whether they reflect other factors. In fact, the effect of in-trial blood pressure levels on the progression of renal failure in hypertension has not been adequately evaluated. As part of the multi-center African American Study of Kidney Disease and Hypertension (AASK) Full Scale Trial, we propose to utilize the protocol and experience of the AASK pilot group to study the effects of lowering blood pressure to two different targets: 1) mean arterial blood pressure (MABP) 102-107 and 2) MABP <92 on renal function (glomerular filtration) utilizing three different antihypertensive regimens (an angiotensin converting enzyme inhibitor, a calcium channel blocker and a beta-blocker) in 90 subjects. Specific expertise brought to this project by the investigators include a unique relationship with the African American community of Ann Arbor, MI, extensive experience with the successful implementation and completion of clinical trials in both hypertension and measurement of renal function by iothalamate clearance, and special expertise in the area of epidemiology of ESRD and, specifically, of racial differences in etiology of ESRD. The African American community in Ann Arbor, MI, is neither "inner-city" nor "rural," and therefore offers an important opportunity to recruit subjects who help describe the heterogeneity of the African American population in the U.S.